CN114347284A

CN114347284A - Cutting device

Info

Publication number: CN114347284A
Application number: CN202111175023.2A
Authority: CN
Inventors: 美细津祐成
Original assignee: Disco Corp
Current assignee: Disco Corp
Priority date: 2020-10-13
Filing date: 2021-10-09
Publication date: 2022-04-15
Also published as: KR20220048933A; TW202215574A; JP2022064024A

Abstract

The invention provides a cutting device, which prevents the adhesion of cutting chips. When a wafer (140) is cut by moving a chuck table (2) in a cutting feed direction, namely-X direction, using a cutting feed unit (26) in a state where a rotating cutting tool (310) cuts into the wafer (140) held by the chuck table (2), water is sprayed from a water nozzle (60) in the-X direction, which is the forward direction with respect to the cutting feed direction of the chuck table (2), and air is sprayed from an air nozzle (61). As a result, a water flow in the-X direction is generated on the upper surface (1400) of the wafer (140), and grinding chips generated by grinding of the wafer (140) are washed away from the upper surface (1400) of the wafer (140) in the-X direction.

Description

Cutting device

Technical Field

The present invention relates to a cutting device.

Background

In a cutting apparatus for cutting a wafer held on a chuck table by using a cutting tool, the upper surface of the wafer is covered with water during cutting so that cutting chips generated by grinding the wafer do not adhere to the upper surface of the wafer. As disclosed in patent document 1, the wafer is cut by performing cutting feed to the chuck table while spreading water over the entire upper surface of the wafer.

However, the flow of water on the upper surface of the wafer is small or no, and the gap between the lower surface of the spindle unit, which rotates the cutting tool, and the upper surface of the wafer is filled with water, and the upper surface of the wafer and the lower surface of the spindle unit are joined by the water.

Therefore, the water on the upper surface of the wafer does not flow, and the chips are retained in the water layer on the upper surface of the wafer and adhere to the upper surface of the wafer.

Further, as disclosed in patent documents 2 and 3, there is an invention in which a water tank is formed and the entire upper surface of the wafer is covered with water. In this case, the water on the upper surface of the wafer does not flow, and chips are attached to the upper surface of the wafer.

Patent document 1: japanese patent laid-open publication No. 2005-222990

Patent document 2: japanese patent laid-open publication No. 2001-135596

Patent document 3: japanese patent laid-open publication No. 2017-094455

Therefore, the cutting device has the following problems: a water layer in which water flows is formed on the upper surface of the wafer, thereby preventing adhesion of swarf.

Disclosure of Invention

The cutting device of the invention comprises: a chuck table that holds a wafer on a holding surface; a cutting unit in which a cutting tool for cutting the wafer is disposed at a tip of the spindle, the cutting unit cutting the wafer held by the holding surface; and a cutting feed unit that cuts the wafer by cutting-feeding the chuck table in a cutting feed direction that is a forward direction with respect to a rotation direction of the cutting tool, wherein the cutting device includes: a water nozzle which extends parallel to the spindle and is disposed on an upstream side in the cutting feed direction, and which sprays water in a forward direction with respect to the cutting feed direction of the chuck table on which the cutting feed is performed, thereby forming a water layer on an upper surface of the wafer held by the holding surface; and an air nozzle extending parallel to the spindle and the water nozzle, for causing air to flow in a forward direction on an upper surface of the water layer with respect to the cutting feed direction.

Preferably, in the cutting device, the water nozzle and the air nozzle are disposed adjacent to the chuck table, and the water nozzle and the air nozzle are moved in the cutting feed direction together with the chuck table.

The air nozzle may spray two fluids obtained by mixing water with air.

In the cutting apparatus of the present invention, water is sprayed from the water nozzle and air is sprayed from the air nozzle during grinding of the wafer, so that a flow of water is generated on the upper surface of the wafer, and grinding chips generated by grinding of the wafer can be washed away from the upper surface of the wafer.

Drawings

Fig. 1 is a perspective view showing the entire cutting device.

Fig. 2 is a sectional view of the cutting unit and the holding unit.

Fig. 3 is a sectional view of the cutting unit and the holding unit.

Description of the reference symbols

1: a cutting device; 10: a base; 100: a box loading platform; 11: a gate post; 14: a workpiece unit; 140: a wafer; 141: a frame; 142: a belt; 1400: an upper surface; 1401: a device; 1402: dividing the predetermined line; 2: a chuck table; 20: a suction part; 200: a holding surface; 21: a frame body; 210: an upper surface; 23: a clamp; 26: a cutting feed unit; 27: a cover; 28: creasing; 29: an attraction source; 30: a cutting tool; 31: 1 st cutting unit; 32: a 2 nd cutting unit; 33: a shooting unit; 310: a cutting tool; 311: a spindle housing; 312: 1, a main shaft; 320: a cutting tool; 321: a spindle housing; 322: a 2 nd main shaft; 41: a 1 st Z-axis moving unit; 42: a 2 nd Z-axis moving unit; 410: a ball screw; 411: a guide rail; 412: a Z-axis motor; 413: a lifting plate; 415: a rotation axis; 420: a ball screw; 421: a guide rail; 422: a Z-axis motor; 423: a lifting plate; 425: a rotation axis; 51: a 1 st Y-axis moving unit; 52: a 2 nd Y-axis moving unit; 510: a ball screw; 511: a guide rail; 513: a sliding plate; 520: a ball screw; 521: a guide rail; 522: a Y-axis motor; 523: a sliding plate; 60: a water nozzle; 61: an air nozzle; 600: a water supply source; 610: an air supply source; 62: a water layer; 8: a cutting water nozzle; 9: the cutting water provides a source.

Detailed Description

1 Structure of cutting device

The cutting apparatus 1 shown in fig. 1 is a cutting apparatus for cutting a wafer 140 by using a 1 st cutting unit 31 and a 2 nd cutting unit 32. In a state where the wafer 140 is positioned inside the annular frame 141, the tape 142 is attached to the lower surface of the frame 141 and the lower surface of the wafer 140, thereby forming the workpiece unit 14 in which the wafer 140, the frame 141, and the tape 142 are integrated. A plurality of lines to divide 1402 perpendicular to each other are formed on the upper surface 1400 of the wafer 140, and devices 1401 are arranged in regions partitioned by the lines to divide 1402. The following describes the structure of the cutting apparatus 1.

As shown in fig. 1, the cutting apparatus 1 has a base 10 extending in a horizontal direction. The portion of the base 10 on the + X direction side and the-Y direction side serves as a cassette mounting table 100, and a not-shown cassette accommodating the workpiece unit 14 is mounted on the cassette mounting table 100.

A gate post 11 is provided upright on the-X direction side of the base 10. A 1 st Z-axis moving unit 41 that supports the 1 st cutting unit 31 to be movable up and down is disposed on the + X direction side and the + Y direction side of the gate column 11.

The 1 st Z-axis moving unit 41 includes: a ball screw 410 having a rotation axis 415 in a Z-axis direction; a guide rail 411 disposed parallel to the ball screw 410; a Z-axis motor 412 that rotates the ball screw 410 about a rotation axis 415; and an elevating plate 413, a nut of a side portion of which is screwed with the ball screw 410, the elevating plate 413 being in sliding contact with the guide rail 411. The spindle case 311 is coupled to the lifting plate 413.

By rotating the ball screw 410 using the Z-axis motor 412, the lifting plate 413 moves in the Z-axis direction while being guided by the guide rail 411, and the spindle housing 311 coupled to the lifting plate 413 moves in the Z-axis direction.

The 1 st cutting unit 31 has a cutting tool 310, a spindle housing 311, and a 1 st spindle 312 housed inside the spindle housing 311. The 1 st spindle 312 extends in the Y-axis direction, and a cutting tool 310 is attached to the-Y direction side of the 1 st spindle 312. The 1 st spindle 312 is coupled to a motor or the like, not shown, and when the 1 st spindle 312 is driven to rotate by the motor, the cutting tool 310 coupled to the 1 st spindle 312 rotates.

An imaging unit 33 having a camera or the like is disposed adjacent to the cutting tool 310. The imaging unit 33 can be used to image the lines to divide 1402 formed on the wafer 140 held on the holding surface 200 of the chuck table 2.

A 2Z-axis moving unit 42 that supports the 2 nd cutting unit 32 to be movable up and down is disposed on the + X direction side and the-Y direction side of the gate column 11.

The 2 nd Z-axis moving means 42 is configured similarly to the 1 st Z-axis moving means 41. That is, the 2 nd Z-axis moving unit 42 includes: a ball screw 420 having a rotation axis 425 in a Z-axis direction; a guide rail 421 disposed parallel to the ball screw 420; a Z-axis motor 422 for rotating the ball screw 420 about a rotation axis 425; and an elevating plate 423 having a nut at a side thereof screwed to the ball screw 420, the elevating plate 423 being in sliding contact with the guide rail 421. The main shaft housing 321 is coupled to the lift plate 423.

When the ball screw 420 is rotated by the Z-axis motor 422, the lifting plate 423 moves in the Z-axis direction while being guided by the guide rail 421, and the spindle housing 321 coupled to the lifting plate 423 moves in the Z-axis direction accordingly.

The 2 nd cutting unit 32 is configured similarly to the 1 st cutting unit 31. That is, the 2 nd cutting unit 32 includes a cutting tool 320, a spindle housing 321, and a 2 nd spindle 322 housed in the spindle housing 321. The 2 nd spindle 322 is extended in the Y axis direction, and the cutting tool 320 is rotatably attached to the + Y direction side of the 2 nd spindle 322. The 2 nd spindle 322 is coupled to a motor or the like, not shown, and when the 2 nd spindle 322 is driven to rotate by the motor, the cutting tool 320 attached to the 2 nd spindle 322 rotates.

A 1 st Y-axis moving unit 51 for moving the 1 st cutting unit 31 in the Y-axis direction and a 2 nd Y-axis moving unit 52 for moving the 2 nd cutting unit 32 in the Y-axis direction are arranged on the gantry 11.

The 1 st Y-axis moving unit 51 has: a ball screw 510 having an axial center in the Y-axis direction; a Y-axis motor (not shown) that rotates the ball screw 510; a guide rail 511 disposed parallel to the ball screw 510; and a slide plate 513 in which a nut on a side thereof is screwed with the ball screw 510, and the slide plate 513 is in sliding contact with the guide rail 511. The sliding plate 513 supports the 1 st Z-axis moving unit 41.

When the ball screw 510 is rotated by using the Y-axis motor, the slide plate 513 is guided by the guide rails 511 and moves in the Y-axis direction, and accordingly, the 1 st Z-axis moving unit 41 supported by the slide plate 513 and the 1 st cutting unit 31 of the lifting plate 413 supported by the 1 st Z-axis moving unit 41 move integrally in the Y-axis direction.

The 2 nd Y-axis moving unit 52 is configured similarly to the 1 st Y-axis moving unit 51. That is, the 2 nd Y-axis moving unit 52 has: a ball screw 520 having an axial center 525 in the Y-axis direction; a Y-axis motor 522 that rotates the ball screw 520; a guide rail 521 disposed in parallel with the ball screw 520; and a slide plate 523 having a nut on a side thereof screwed to the ball screw 520, the slide plate 523 being in sliding contact with the rail 521.

When the ball screw 520 is rotated by the Y-axis motor 522, the slide plate 523 is guided by the guide rail 521 to move in the Y-axis direction, and along with this, the 2 nd Z-axis moving unit 42 supported by the slide plate 523 and the 2 nd cutting unit 32 supported by the elevating plate 423 of the 2 nd Z-axis moving unit 42 move integrally in the Y-axis direction. The guide rail 521 also serves as a guide for moving the sliding plate 513 of the 1 st Y-axis moving unit 51, and similarly, the guide rail 511 of the 1 st Y-axis moving unit 51 also serves as a guide for moving the sliding plate 523 of the 2 nd Y-axis moving unit 52.

A chuck table 2 is disposed above the base 10. The chuck table 2 includes a disk-shaped suction portion 20 and an annular frame 21 that supports the suction portion 20. The upper surface of the suction portion 20 is a holding surface 200 for holding the workpiece unit 14, and the upper surface 210 of the frame 21 is formed to be flush with the holding surface 200.

At a position adjacent to the chuck table 2, 4 jigs 23 are arranged so as to surround the chuck table 2 from the periphery. The workpiece unit 14 is placed on the holding surface 200 with the upper surface 1400 facing the + Z direction so that the tape 142 contacts the holding surface 200, and the frame 141 is clamped from four sides by using the four clamps 23, whereby the workpiece unit 14 can be fixed to the holding surface 200.

The chuck table 2 is connected to a suction source 29. By operating the suction source 29, the generated suction force is transmitted to the holding surface 200. For example, the wafer 140 can be sucked and held on the holding surface 200 by placing the workpiece unit 14 on the holding surface 200 and operating the suction source 29.

The chuck table 2 is connected to a rotation unit, not shown. By using this rotation unit, the chuck table 2 can be rotated.

The cutting apparatus 1 includes a cutting feed unit 26 that horizontally moves the chuck table 2 in the X-axis direction. For example, in a state where the wafer 140 is held on the holding surface 200 of the chuck table 2, the wafer 140 can be moved in the X-axis direction by horizontally moving the chuck table 2 in the X-axis direction using the cutting feed unit 26.

A cover 27 is disposed around the chuck table 2, and the cover 27 is connected to the bellows 28 so as to be able to expand and contract.

When the chuck table 2 moves in the X-axis direction, the cover 27 moves in the Y-axis direction integrally with the chuck table 2, and the bellows 28 expands and contracts.

The cutting apparatus 1 has a water nozzle 60. The water nozzle 60 is disposed to extend parallel to the Y-axis direction, which is the extending direction of the 1 st spindle 312 and the 2 nd spindle 322, and is disposed on the + X direction side, which is the upstream side in the cutting feed direction. As shown in fig. 2, the water nozzle 60 is disposed at a horizontal position adjacent to the chuck table 2 and fixed above the jig 23 disposed on the + X direction side of the chuck table 2. In addition, the injection port of the water nozzle 60 is directed in a direction between the-X direction and the-Z direction.

The water nozzle 60 is connected to a water supply source 600, and water can be sprayed toward the holding surface 200 of the chuck table 2 by supplying water from the water supply source 600 to the water nozzle 60.

The cutting device 1 has an air nozzle 61. The air nozzle 61 is disposed to extend in parallel with the 1 st spindle 312, the 2 nd spindle 322, and the water nozzle 60. The ejection port of the air nozzle 61 faces in a direction between the-X direction and the-Z direction. The air nozzle 61 is connected to an air supply source 610. By supplying air from the air supply source 610 to the air nozzle 61, air can be ejected from the air nozzle 61 toward the holding surface 200 from, for example, 30 degrees above. Further, for example, by ejecting air from the air nozzle 61 while ejecting water from the water nozzle 60, the air ejected from the air nozzle 61 flows on the water surface of the water ejected from the water nozzle 60 and supplied to the holding surface 200, thereby forming a water flow in the water on the holding surface 200.

Instead of the above configuration, the air nozzle 61 may be a mixed fluid nozzle integrated with the water nozzle 60, and may eject two fluids obtained by mixing water with air.

The 1 st cutting unit 31 is provided with a cutting water nozzle 8 for spraying cutting water to a machining point where the cutting blade 310 contacts the upper surface 1400 of the wafer 140. The cutting water nozzle 8 is connected to a cutting water supply source 9. By supplying cutting water from the cutting water supply source 9 to the cutting water nozzle 8, the cutting water can be ejected from the cutting water nozzle 8 toward the machining point.

2 operation of the cutting device

The operation of the cutting apparatus 1 when the wafer 140 is cut by the cutting apparatus 1 will be described.

When the wafer 140 is cut by the cutting apparatus 1, first, the workpiece unit 14 shown in fig. 1 is placed on the holding surface 200, and the frame 141 is held and fixed by the 4 jigs 23. Then, the suction force generated by operating the suction source 29 is transmitted to the holding surface 200, and the tape 142 is sucked to the holding surface 200, and the wafer 140 is held on the holding surface 200.

Next, the chuck table 2 is moved in the-X direction by the cutting feed unit 26, and the wafer 140 held by the chuck table 2 is positioned below the imaging unit 33.

After the wafer 140 is positioned below the imaging unit 33, the predetermined dividing lines 1402 formed on the wafer 140 are imaged by the imaging unit 33. Then, based on the photographed image of the line to divide 1402, the 1 st cutting unit 31 and the 2 nd cutting unit 32 are appropriately moved in the Y axis direction by the 1 st Y axis moving unit 51 and the 2 nd Y axis moving unit 52, and the 1 st cutting unit 31 and the 2 nd cutting unit 32 are aligned in the Y axis direction with respect to the line to divide 1402.

Then, as shown in fig. 2, in a state where the

cutting tools

310 and 320 are rotated, the 1 st cutting unit 31 is moved in the-Z direction by using the 1 st Z-axis moving unit 41 and the 2 nd Z-axis moving unit 42 shown in fig. 1, and the

rotating cutting tools

310 and 320 are brought into contact with the planned dividing line 1402 of the wafer 140.

In a state where the

rotating cutting tools

310 and 320 cut into the planned dividing line 1402 of the wafer 140, the wafer 140 held on the chuck table 2 is moved in a cutting feed direction (-X direction) which is a forward direction with respect to the rotation direction of the

cutting tools

310 and 320 by using the cutting feed unit 26.

Thereby, the wafer 140 and the

cutting tools

310 and 320 are relatively moved in the X-axis direction, and the wafer 140 is cut along the planned dividing line 1402 of the wafer 140. At this time, the water nozzle 60 and the air nozzle 61 move in the cutting feed direction together with the chuck table 2.

When the wafer 140 is cut, chips are generated. Therefore, in the grinding process of the wafer 140, as shown in fig. 2, water is sprayed from the water spray nozzles 60 in a direction between the-X direction and the-Z direction. Thereby, water flows on the upper surface 1400 of the wafer 140 in the forward direction (-X direction) with respect to the cutting feed direction of the chuck table 2, and the water spreads over the upper surface 1400 of the wafer 140, and as shown in fig. 3, a water layer 62 is formed on the upper surface 1400 of the wafer 140.

Air is ejected from the air nozzle 61 in a direction between the-X direction and the-Z direction, and is ejected in a forward direction with respect to the cutting feed direction toward the upper surface of the water layer 62 formed on the upper surface 1400 of the wafer 140. This forms a water flow on the upper surface 1400 of the wafer 140, and the chips accumulated in the water layer 62 formed on the upper surface 1400 of the wafer 140 can be washed away from the upper surface 1400 of the wafer 140 toward the-X direction.

After the cutting of the 1 planned dividing line 1402 is performed, the chuck table 2 is moved in the + X direction and returned to the original position, and for example, the 1 st cutting unit 31 and the 2 nd cutting unit 32 are moved in the Y axis direction by the interval between the adjacent planned dividing lines 1402 by using the 1 st Y axis moving unit 51 and the 2 nd Y axis moving unit 52, and the cutting tool 30 is cut into the planned dividing lines 1402 and fed in the same manner, thereby cutting the adjacent planned dividing lines 1402.

After all the planned dividing lines 1402 formed in the same direction on the wafer 140 are cut in this way, the chuck table 2 is rotated by, for example, 90 degrees by using a not-shown rotating unit, and then similarly cut, thereby cutting all the planned dividing lines 1402 on the wafer 140. Thereby, all the lines to divide 1402 formed on the wafer 140 are cut.

In the cutting apparatus 1, water is sprayed from the water nozzles 60 and air is sprayed from the air nozzles 61 during grinding of the wafer 140, so that a water flow is generated on the upper surface 1400 of the wafer 140, and grinding chips generated by the grinding of the wafer 140 can be washed away from the upper surface 1400 of the wafer 140.

Further, the conventional cutting apparatus needs to include a cleaning unit, not shown, for cleaning the upper surface 1400 of the wafer 140 after the cutting process, but in the cutting apparatus 1, when the planned dividing line 1402 formed in the wafer 140 is relatively small and the number of chips generated by the cutting process is relatively small, for example, the cleaning of the upper surface 1400 of the wafer 140 by the cleaning unit can be omitted by cleaning the upper surface 1400 of the wafer 140 using the water ejected from the water nozzle 60 and the air ejected from the air nozzle 61. In this case, the cutting apparatus 1 does not need the cleaning unit, and the cutting apparatus can be downsized.

The cutting device 1 may be an edge trimming device that performs cutting in a ring shape along the outer peripheral edge of the wafer.

Claims

1. A cutting device, comprising:

a chuck table that holds a wafer on a holding surface;

a cutting unit in which a cutting tool for cutting the wafer is disposed at a tip of the spindle, the cutting unit cutting the wafer held by the holding surface; and

a cutting feed unit that cuts the wafer by cutting feeding the chuck table in a cutting feed direction that is a forward direction with respect to a rotation direction of the cutting tool,

wherein, this cutting device has:

a water nozzle which extends parallel to the spindle and is disposed on an upstream side in the cutting feed direction, and which sprays water in a forward direction with respect to the cutting feed direction of the chuck table on which the cutting feed is performed, thereby forming a water layer on an upper surface of the wafer held by the holding surface; and

an air nozzle extending parallel to the spindle and the water nozzle, for flowing air in a forward direction relative to the cutting feed direction on the upper surface of the water layer.

2. The cutting apparatus of claim 1,

the water nozzle and the air nozzle are disposed adjacent to the chuck table so as to be moved together with the chuck table in the cutting feed direction.

3. The cutting apparatus of claim 1,

the air nozzle sprays two fluids obtained by mixing water in air.